CN110940645A - Portable fluorescence sensing platform for cadmium ion detection and detection method - Google Patents

Portable fluorescence sensing platform for cadmium ion detection and detection method Download PDF

Info

Publication number
CN110940645A
CN110940645A CN201911035710.7A CN201911035710A CN110940645A CN 110940645 A CN110940645 A CN 110940645A CN 201911035710 A CN201911035710 A CN 201911035710A CN 110940645 A CN110940645 A CN 110940645A
Authority
CN
China
Prior art keywords
solution
platform
smart phone
micro
fluorescence
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN201911035710.7A
Other languages
Chinese (zh)
Other versions
CN110940645B (en
Inventor
王平
王心怡
孔留兵
甘颖
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhejiang University ZJU
Original Assignee
Zhejiang University ZJU
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zhejiang University ZJU filed Critical Zhejiang University ZJU
Priority to CN201911035710.7A priority Critical patent/CN110940645B/en
Publication of CN110940645A publication Critical patent/CN110940645A/en
Application granted granted Critical
Publication of CN110940645B publication Critical patent/CN110940645B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
    • G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
    • G01N21/64—Fluorescence; Phosphorescence
    • G01N21/6402—Atomic fluorescence; Laser induced fluorescence
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
    • G01N1/38—Diluting, dispersing or mixing samples

Landscapes

  • Health & Medical Sciences (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Optics & Photonics (AREA)
  • Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)

Abstract

The invention discloses a portable fluorescence sensing platform for cadmium ion detection and a detection method. According to the platform, a micro-fluidic chip processed by PDMS is used as a solution cavity, ultraviolet LEDs on two sides excite the solution in the solution cavity, the generated fluorescence is collected by a camera of a smart phone, and finally the fluorescence intensity is determined. The detection method is a method for etching CdTe/CdS core-shell Quantum Dots (QDs) by Ethylene Diamine Tetraacetic Acid (EDTA). Etching of the surface of CdTe/CdS QDs by addition of EDTA to produce specific Cd2+Recognition sites, resulting in fluorescence quenching; when Cd is added2+Thereafter, Cd2+These etch sites can be specifically recognized, resulting in fluorescence recovery. Whereas the recovery efficiency of fluorescence is directly dependent on the added Cd2+Thus the fluorescence intensity reflects Cd2+The concentration and fluorescence intensity of the fluorescent substance can be detected by the portable platform. The invention has the advantages of rapid detection, low detection limit and the like.

Description

Portable fluorescence sensing platform for cadmium ion detection and detection method
Technical Field
The invention relates to the field of cadmium ion detection, in particular to a portable fluorescence sensing platform for cadmium ion detection and a detection method.
Background
Cadmium ion (Cd)2+) Is a heavy metal ion with strong toxicity, is easy to be enriched in various organs of a human body, and has direct influence on the health of the human body. At present, the traditional cadmium ion analysis technology such as atomic absorption spectroscopy, inductively coupled plasma mass spectrometry, electrochemical methods and the like has the limitations of large volume, high cost, complex operation and time consumption, so that the practical application of the cadmium ion analysis technology in field detection is limited. Recently, many researchers have used smartphones as detection elements for various analysis methods because it has not only the advantages of portability and low cost, but also data storage, data processing, and data sharing capabilities. Therefore, the smart phone can be combined with a cadmium ion detection method to form a novel portable cadmium ion fluorescence detection device. Cd combined with smart phone is not available so far2+A fluorescence sensing platform for field measurement and a detection method. Therefore, a simple, rapid, reliable and highly selective portable fluorescence sensing platform and a detection method for trace Cd2+The field test of (1).
Disclosure of Invention
The invention aims to provide a portable fluorescence sensing platform for cadmium ion detection and a detection method aiming at the defects of the prior art.
The purpose of the invention is realized by the following technical scheme: a portable fluorescence sensing platform for cadmium ion detection, the platform comprising: the system comprises a platform shell, a smart phone clamping groove, a smart phone camera, a macro lens, an optical filter, a Micro-fluidic chip, a first stainless steel tube, a second stainless steel tube, a first ultraviolet LED, a second ultraviolet LED, a power supply circuit board, a Micro-USB charging port, a switch, an injection pump, an injector, a waste liquid cylinder and a Micro-fluidic chip clamping groove;
the portable fluorescence sensing platform is provided with a power supply circuit board, and the power supply circuit board is provided with a Micro-USB charging port; a micro-fluidic chip clamping groove is fixed at the bottom of the platform casing and used for placing a micro-fluidic chip, a first ultraviolet LED and a second ultraviolet LED are arranged on two sides of the micro-fluidic chip and are powered by a power supply circuit board, and the opening and closing of the ultraviolet LEDs are controlled by a switch on the side surface of the platform casing; the microfluidic chip is composed of a glass slide and a PDMS-processed cavity, a first stainless steel pipe and a second stainless steel pipe are inserted into two ends of the cavity, the first stainless steel pipe is connected with an injector on the injection pump to control the input of liquid, and the second stainless steel pipe is connected with a waste liquid cylinder to control the output of liquid; a smart phone card slot is arranged above the platform shell, and the smart phone is horizontally placed in the smart phone card slot; a round hole is formed in the top of the platform shell, the round hole is arranged right above the cavity of the microfluidic chip, and a macro lens and an optical filter are sequentially adhered below the round hole; the smart phone camera is arranged right above the round hole, and can be used for collecting images of samples in the cavity processed by PDMS of the microfluidic chip through the round hole.
Furthermore, the power supply circuit board is powered by a lithium battery, the output voltage of the lithium battery is 3.8V, the output voltage of the power supply circuit board is 3.5V, power is supplied to the two ultraviolet LEDs, and the excitation wavelength of the ultraviolet LEDs is 365 nm.
Further, the volume of the PDMS processed cavity was 75 μ L.
Furthermore, the diameter of the circular hole at the top of the platform shell is 10mm, and the diameters of the macro lens and the optical filter are 25 mm. The optical filter is 500nm wavelength pass and can filter ultraviolet exciting light.
Further, the centers of the circular hole at the top of the shell, the macro lens and the optical filter are coaxial.
Furthermore, the power supply circuit board is connected with a green indicator light and a red indicator light, the green indicator light and the red indicator light are exposed outside through an opening in the platform shell, when the battery is charged through the Micro-USB charging port, the green indicator light is on, and when the battery is fully charged, the red indicator light is on.
A cadmium ion fluorescence detection method based on a portable fluorescence sensing platform comprises the following steps:
(1) preparing a cadmium ion detection solution: adding 4740 μ l 10mM Tris-HCl buffer solution with pH 8.5, 660 μ l 100 μ M EDTA and 600 μ l 4 μ M CdTe/CdS quantum dots QDs into a 10mL test tube in sequence, and mixing the solution uniformly; sealing the test tube, and placing the test tube in a dark place to react for 10 minutes at room temperature to obtain an EDTA-CdTe/CdS QDs mixed solution;
(2)Cd2+preparing a standard solution: by introducing Cd at different concentration levels2+Preparing all samples, and obtaining Cd doped with different concentration levels2+The labeled sample of (1); and adjusting the pH value of the spiked sample solution to 8.5 by using 10mM Tris-HCl buffer solution with the pH value of 8.5;
(3) determining an optimal calibration curve for detecting cadmium ions: adding equal volumes of Cd at different concentration levels into 500 μ l of EDTA-CdTe/CdSQDs solution prepared in step (1)2+Adding the solution into a standard solution, fully mixing the solution, and reacting for 20 minutes in a dark place; sequentially pumping the reacted final solution into a disposable injector, and opening a switch on the side surface of the platform shell; placing a disposable injector on an injection pump, wherein the disposable injector is connected to an injection port of the portable fluorescence sensing platform through a connector, and an outlet of the portable fluorescence sensing platform is connected to a waste liquid cylinder; the method comprises the following steps of carrying out image acquisition on each sample through a smart phone, processing each acquired image after all images are acquired, wherein the acquisition and processing process of the sample images comprises the following substeps:
(3.1) opening a camera of the smart phone, setting the camera to be in a professional photographing mode, and setting camera parameters of the smart phone;
and (3.2) starting an injection pump, setting parameters of the injection pump, when the solution is injected into a cavity of a micro-fluidic chip of the portable fluorescence sensing platform, carrying out image acquisition by using a smart phone under the shooting parameters, and continuously acquiring n pictures for each sample at a certain time interval. After image acquisition for each sample was completed. Cleaning with an injector filled with air;
(3.3) after the images of all the samples are collected, processing each collected image; selecting a central area of m pixel points of the cavity part in each photo, selecting a G channel of an RGB channel for analysis, and averaging G values of the m pixel points to obtain a fluorescence intensity value Ig(ii) a Based on the above processing procedure, n images collected from each sample are analyzed to obtain n fluorescence intensities IgValue n fluorescence intensities IgThe values are averaged to obtain
Figure BDA0002251689070000032
A value; obtained by analyzing each sample
Figure BDA0002251689070000033
Value minus control Tris-HCl buffer corresponding to Ig-trisAfter the value, the value I is obtained, i.e.
Figure BDA0002251689070000031
Adding no Cd2 +The value obtained by calculation by using the EDTA-CdTe/CdS QDs solution as a blank group is marked as I0(ii) a Then, the ratio I/I is used0As an index, the concentration of cadmium ion and the ratio I/I are plotted0Curve (c) of (d). Then, fitting a curve algorithm according to a least square method to obtain the concentration of cadmium ions and the ratio I/I0Obtaining the optimal calibration curve of the concentration of cadmium ions according to the linear relation;
(4) detecting the concentration of cadmium ions in an aqueous solution with unknown concentration: regulating the pH value of a solution to be detected with unknown concentration to 8.5 by using a Tris-HCl buffer solution with the pH value of 10mM being 8.5, adding the solution to an EDTA-CdTe/CdS QDs solution, and repeating the steps (1) and (3) to obtain the fluorescence intensity ratio I/I corresponding to the solution to be detected0And (4) substituting the optimal calibration curve for detecting the cadmium ion concentration obtained in the step (3) to calculate the cadmium ion concentration of the sample solution to be detected.
The invention has the beneficial effects that: the invention realizes the on-site rapid monitoring of the concentration of cadmium ions and has the advantages of rapid detection, low detection limit, simple and convenient operation, low cost and the like. Compared with the existing cadmium ion concentration detection method, the method provided by the invention overcomes the defect that the existing method cannot carry out on-site rapid and portable monitoring. According to the advantages, the device and the method can be widely applied to the related fields of environmental monitoring, food safety, heavy metal detection and the like.
Drawings
FIG. 1 is an overall structure diagram of a portable fluorescence sensing platform for cadmium ion detection according to the present invention;
FIG. 2 is a partial block diagram of a microfluidic chip module according to the present invention;
FIG. 3 is a graph of the change in the EDTA concentration versus the CdTe/CdS quantum dot fluorescence ratio of the present invention;
FIG. 4 is a graph showing the results of an optimal calibration curve for cadmium ions determined by the present invention;
FIG. 5 is a flow chart of the method of the present invention;
in the figure, 1, a platform shell, 2, a smart phone, 3, a smart phone clamping groove, 4, a smart phone camera, 5, a macro lens, 6, an optical filter, 7, a Micro-fluidic chip, 8, PDMS, 9, a cavity, 10, a glass slide, 11, a first stainless steel tube, 12, a second stainless steel tube, 13, a first ultraviolet LED, 14, a second ultraviolet LED, 15, a power supply circuit board, 16, a lithium battery, 17, a Micro-USB charging port, 18, a green indicator light, 19, a red indicator light, 20, a switch, 21, an injection pump, 22, an injector, 23, a waste liquid cylinder and 24, the Micro-fluidic chip clamping groove.
Detailed Description
The invention is described in further detail below with reference to the figures and the specific embodiments, but without limiting the invention.
As shown in fig. 1 and 2, the present invention provides a portable fluorescence sensing platform for cadmium ion detection, for portable detection of fluorescence intensity, the platform comprising: the system comprises a platform shell 1, a smart phone 2, a smart phone card slot 3, a smart phone camera 4, a macro lens 5, an optical filter 6, a Micro-fluidic chip 7, PDMS8, a cavity 9, a glass slide 10, a first stainless steel tube 11, a second stainless steel tube 12, a first ultraviolet LED13, a second ultraviolet LED14, a power supply circuit board 15, a lithium battery 16, a Micro-USB charging port 17, a green indicator lamp 18, a red indicator lamp 19, a switch 20, an injection pump 21, an injector 22, a waste liquid cylinder 23 and a Micro-fluidic chip card slot 24; wherein, power supply circuit board 15 is fixed in casing 1 bottom left side, and the Micro-USB on it charges mouthful 17 and exposes outside through the opening on the casing, connects two pilot lamps on the power supply circuit board 15: the green indicator light 18 and the red indicator light 19 are exposed outside through an opening on the shell, when the Micro-USB charging port 17 is used for charging the lithium battery 16, the green indicator light 18 is on, and when the battery is fully charged, the red indicator light 19 is on; a micro-fluidic chip clamping groove 24 is fixed on the right side of the bottom of the machine shell 1, the micro-fluidic chip 7 is placed through the clamping groove 24, two ultraviolet LEDs 13 and 14 are placed on two sides of the micro-fluidic chip 7, the excitation wavelength of the ultraviolet LEDs is 365nm, power is supplied by a power supply circuit board 15, the power supply voltage is 3.5V, and the on and off of the micro-fluidic chip can be controlled through a switch 20 on the side face of the machine shell 1; the microfluidic chip 7 is composed of a glass slide 10 and a cavity 9 processed by PDMS8, the volume of the cavity is about 75 μ L, and PDMS8 is a good light-transmitting material; two stainless steel pipes 11 and 12 are inserted into two ends of the cavity 9, the first stainless steel pipe 11 is connected with an injector 22 on an injection pump 21 to control the input of liquid, and the second stainless steel pipe 12 is connected with a waste liquid cylinder 23 to control the output of liquid; a smart phone card slot 3 is arranged above the shell 1, and a smart phone 2 is horizontally placed in the smart phone card slot 3; the top of the shell is provided with a round hole, the round hole is arranged right above a cavity 9 of the microfluidic chip 7, the lower part of the round hole is sequentially pasted with the macro lens 5 and the optical filter 6, the diameter of the round hole is 10mm, the diameter of the macro lens 5 and the diameter of the optical filter 6 are 25mm, and the centers of the round hole on the top of the shell, the macro lens 5 and the optical filter 6 are coaxial. The macro lens 5 can effectively shorten the imaging distance of the mobile phone and reduce the size of the instrument. The optical filter 6 is a 500nm long-wave pass filter which can filter ultraviolet exciting light; the smart phone camera 4 is right above the round hole, and can collect images of samples in the cavity 9 of the micro-fluidic chip through the round hole.
As shown in fig. 5, a method for cadmium ion fluorescence detection based on a smart phone includes the following steps:
(1) preparing a cadmium ion detection solution: 4740. mu.l of 10mM Tris-HCl (Tris-hydrochloride) buffer solution at pH 8.5, 660. mu.l of 100. mu.M EDTA and 600. mu.l of 4. mu.M CdTe/CdS Quantum Dots (QDs) were added to a 10mL test tube in this order, and the solutions were mixed well. Sealing the test tube, and placing the test tube in a dark place to react for 10 minutes at room temperature to obtain an EDTA-CdTe/CdS QDs mixed solution;
(2)Cd2+preparing a standard solution: by introducing Cd at different concentration levels2+Preparing all samples, and obtaining Cd doped with different concentration levels2+The labeled sample of (1); and adjusting the pH of the solution to 8.5 by using 10mM Tris-HCl buffer solution with the pH of 8.5;
(3) determining an optimal calibration curve for detecting cadmium ions: adding 500 μ l of the prepared EDTA-CdTe/CdS QDs solutionEqual volume of Cd2+Add the standard solution, mix the above solution well, and react for 20 minutes in dark. And (4) sequentially pumping the reacted final solutions into a disposable syringe, and opening a switch on the side surface of the shell. The disposable syringe with the final solution drawn is placed on the syringe pump, the disposable syringe is connected by a connector to the injection port of the portable instrument, and the outlet of the portable instrument is connected to the waste liquid tank. And (4) acquiring images of each sample through the smart phone, and processing each acquired image after all the images are acquired. The acquisition and processing process comprises the following substeps:
(3.1) open the camera of smart mobile phone, set up to professional mode of shooing, the cell-phone parameter setting of making a video recording sets up to: sensitivity ISO is 400, exposure time S is 1.0S;
and (3.2) starting the injection pump, setting the injection speed parameter of the injection pump to be 1000 mu L/min, carrying out image acquisition by using a smart phone under the camera shooting parameter when the solution is injected into the detection cavity of the portable instrument, and continuously acquiring 5 pictures for each sample. Cleaning between every two samples by using an injector filled with air;
(3.3) after the images of all the samples are collected, processing each collected image; selecting a central area of m pixel points of the cavity part in each photo, selecting a G channel of an RGB channel for analysis, and averaging G values of the m pixel points to obtain a fluorescence intensity value Ig；
Based on the above process, 5 images obtained from each sample were analyzed to obtain 5 fluorescence intensities IgValue, 5 fluorescence intensities IgThe values are averaged to obtain
Figure BDA0002251689070000051
The value is obtained. Obtained by analyzing each sample
Figure BDA0002251689070000053
Value minus control Tris-HCl buffer corresponding to Ig-trisAfter the value, the value I is obtained, i.e.
Figure BDA0002251689070000052
Figure BDA0002251689070000054
The calculated value of the blank group is recorded as I0(ii) a Then, the ratio I/I is used0As an index, the concentration of cadmium ion and the ratio I/I are plotted0Curve (c) of (d). Then, fitting a curve algorithm according to a least square method to obtain the concentration of cadmium ions and the ratio I/I0Obtaining the optimal calibration curve of the concentration of cadmium ions according to the linear relation;
(4) detecting the concentration of cadmium ions in an aqueous solution with unknown concentration: adjusting the pH value of a solution to be detected with unknown concentration to 8.5 by using a Tris-HCl buffer solution with the pH value of 10mM to 8.5, adding the solution to an EDTA-CdTe/CdS QDs solution, and repeating the steps (1) and (3) to obtain the fluorescence intensity ratio I/I corresponding to the solution to be detected0And (4) substituting the optimal calibration curve for detecting the cadmium ion concentration obtained in the step (3) to calculate the cadmium ion concentration of the sample solution to be detected.
FIG. 3 is a graph of the change in the ratio of EDTA concentration to CdTe/CdS quantum dot fluorescence of the present invention, from which it can be seen that the addition of EDTA causes a significant quenching of the CdTe/CdS QDs fluorescence, leaving it in the off state. As the concentration of EDTA increases, the fluorescence intensity ratio of the CdTe/CdS quantum dots is gradually reduced. This is due to the chemical etching of EDTA, resulting in the generation of CdTe/CdS QDs surface defects and the loss of the surrounding Cd-thiol complex, while fluorescence can be recovered again when cadmium ions are added. The concentration of cadmium ions can thus be detected in this way. FIG. 4 is a graph showing the result of the optimal calibration curve of cadmium ions determined by the present invention, and it can be seen that the cadmium ion detection method based on the portable fluorescence detection platform of the present invention has a good linear correlation with the response of cadmium ion concentration. The optimal calibration curve formula is I/I0＝0.0129CCd 2++1.26，I/I0As the ratio of fluorescence intensities, CCd 2+The concentration of cadmium ions in the sample to be detected. Experimental results prove that the method can accurately detect the concentration of cadmium ions in the sample to be detected.
One skilled in the art can readily devise many variations and modifications without departing from the spirit and scope of the invention as defined in the following claims, from the description and drawings. Any modifications and equivalent variations of the above-described embodiments, which are made in accordance with the technical spirit and substance of the present invention, fall within the scope of protection of the present invention as defined in the claims.

Claims (7)

1. A portable fluorescence sensing platform for cadmium ion detection, the platform comprising: the system comprises a platform shell, a smart phone clamping groove, a smart phone camera, a macro lens, an optical filter, a Micro-fluidic chip, a first stainless steel tube, a second stainless steel tube, a first ultraviolet LED, a second ultraviolet LED, a power supply circuit board, a Micro-USB charging port, a switch, an injection pump, an injector, a waste liquid cylinder and a Micro-fluidic chip clamping groove;
the portable fluorescence sensing platform is provided with a power supply circuit board, and the power supply circuit board is provided with a Micro-USB charging port; a micro-fluidic chip clamping groove is fixed at the bottom of the platform casing and used for placing a micro-fluidic chip, a first ultraviolet LED and a second ultraviolet LED are arranged on two sides of the micro-fluidic chip and are powered by a power supply circuit board, and the opening and closing of the ultraviolet LEDs are controlled by a switch on the side surface of the platform casing; the microfluidic chip is composed of a glass slide and a PDMS-processed cavity, a first stainless steel pipe and a second stainless steel pipe are inserted into two ends of the cavity, the first stainless steel pipe is connected with an injector on the injection pump to control the input of liquid, and the second stainless steel pipe is connected with a waste liquid cylinder to control the output of liquid; a smart phone card slot is arranged above the platform shell, and the smart phone is horizontally placed in the smart phone card slot; a round hole is formed in the top of the platform shell, the round hole is arranged right above the cavity of the microfluidic chip, and a macro lens and an optical filter are sequentially adhered below the round hole; the smart phone camera is arranged right above the round hole, and can be used for collecting images of samples in the cavity processed by PDMS of the microfluidic chip through the round hole.
2. The portable fluorescence sensing platform for cadmium ion detection according to claim 1, wherein the power supply circuit board is powered by a lithium battery with an output voltage of 3.8V and an output voltage of 3.5V, and supplies power to two ultraviolet LEDs with an excitation wavelength of 365 nm.
3. The portable fluorescence sensing platform of claim 1, wherein the volume of the PDMS processed cavity is 75 μ L.
4. The portable fluorescence sensing platform of claim 1, wherein the diameter of the circular hole at the top of the platform housing is 10mm, and the diameter of the macro lens and the optical filter is 25 mm. The optical filter is 500nm wavelength pass and can filter ultraviolet exciting light.
5. The portable fluorescence sensing platform of claim 1, wherein the top circular hole of the housing, the macro lens and the center of the optical filter are coaxial.
6. The portable fluorescence sensing platform of claim 2, wherein the power supply circuit board has a green light and a red light, the green light and the red light are exposed through an opening of the platform housing, the green light is on when the Micro-USB charging port charges the battery, and the red light is on when the battery is fully charged.
7. A cadmium ion fluorescence detection method based on a portable fluorescence sensing platform is characterized by comprising the following steps:
(1) preparing a cadmium ion detection solution: adding 4740 μ l 10mM Tris-HCl buffer solution with pH 8.5, 660 μ l 100 μ M EDTA and 600 μ l 4 μ M CdTe/CdS quantum dots QDs into a 10mL test tube in sequence, and mixing the solution uniformly; sealing the test tube, and placing the test tube in a dark place to react for 10 minutes at room temperature to obtain an EDTA-CdTe/CdS QDs mixed solution;
(2)Cd2+preparing a standard solution: by introducing Cd at different concentration levels2+Preparing all samples, and obtaining Cd doped with different concentration levels2+The labeled sample of (1); and adjusting the pH value of the spiked sample solution to 8.5 by using 10mM Tris-HCl buffer solution with the pH value of 8.5;
(3) determining an optimal calibration curve for detecting cadmium ions: adding equal volumes of Cd with different concentration levels into 500 μ l of EDTA-CdTe/CdS QDs solution prepared in step (1)2+Adding the solution into a standard solution, fully mixing the solution, and reacting for 20 minutes in a dark place; sequentially pumping the reacted final solution into a disposable injector, and opening a switch on the side surface of the platform shell; placing a disposable injector on an injection pump, wherein the disposable injector is connected to an injection port of the portable fluorescence sensing platform through a connector, and an outlet of the portable fluorescence sensing platform is connected to a waste liquid cylinder; the method comprises the following steps of carrying out image acquisition on each sample through a smart phone, processing each acquired image after all images are acquired, wherein the acquisition and processing process of the sample images comprises the following substeps:
(3.1) opening a camera of the smart phone, setting the camera to be in a professional photographing mode, and setting camera parameters of the smart phone;
and (3.2) starting an injection pump, setting parameters of the injection pump, when the solution is injected into a cavity of a micro-fluidic chip of the portable fluorescence sensing platform, carrying out image acquisition by using a smart phone under the shooting parameters, and continuously acquiring n pictures for each sample at a certain time interval. After image acquisition for each sample was completed. Cleaning with an injector filled with air;
(3.3) after the images of all the samples are collected, processing each collected image; selecting a central area of m pixel points of the cavity part in each photo, selecting a G channel of an RGB channel for analysis, and averaging G values of the m pixel points to obtain a fluorescence intensity value Ig(ii) a Based on the above processing procedure, n images collected from each sample are analyzed to obtain n fluorescence intensities IgValue n fluorescence intensities IgThe values are averaged to obtain
Figure FDA0002251689060000021
A value; obtained by analyzing each sample
Figure FDA0002251689060000022
Value minus control Tris-HCl buffer corresponding to Ig-trisAfter the value, the value I is obtained, i.e.
Figure FDA0002251689060000023
Adding no Cd2+The value obtained by calculation by using the EDTA-CdTe/CdS QDs solution as a blank group is marked as I0(ii) a Then, the ratio I/I is used0As an index, the concentration of cadmium ion and the ratio I/I are plotted0Curve (c) of (d). Then, fitting a curve algorithm according to a least square method to obtain the concentration of cadmium ions and the ratio I/I0Obtaining the optimal calibration curve of the concentration of cadmium ions according to the linear relation;
(4) detecting the concentration of cadmium ions in an aqueous solution with unknown concentration: regulating the pH value of a solution to be detected with unknown concentration to 8.5 by using a Tris-HCl buffer solution with the pH value of 10mM being 8.5, adding the solution to an EDTA-CdTe/CdS QDs solution, and repeating the steps (1) and (3) to obtain the fluorescence intensity ratio I/I corresponding to the solution to be detected0And (4) substituting the optimal calibration curve for detecting the cadmium ion concentration obtained in the step (3) to calculate the cadmium ion concentration of the sample solution to be detected.
CN201911035710.7A 2019-10-29 2019-10-29 Portable fluorescence sensing platform for cadmium ion detection and detection method Active CN110940645B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201911035710.7A CN110940645B (en) 2019-10-29 2019-10-29 Portable fluorescence sensing platform for cadmium ion detection and detection method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911035710.7A CN110940645B (en) 2019-10-29 2019-10-29 Portable fluorescence sensing platform for cadmium ion detection and detection method

Publications (2)

Publication Number Publication Date
CN110940645A true CN110940645A (en) 2020-03-31
CN110940645B CN110940645B (en) 2021-10-19

Family

ID=69906311

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201911035710.7A Active CN110940645B (en) 2019-10-29 2019-10-29 Portable fluorescence sensing platform for cadmium ion detection and detection method

Country Status (1)

Country Link
CN (1) CN110940645B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115161019A (en) * 2022-05-11 2022-10-11 华中农业大学 Preparation method of nitrogen-doped luminescent carbon quantum dot and application of nitrogen-doped luminescent carbon quantum dot in rapid detection of lysine content in pig serum

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1591001A (en) * 2003-08-29 2005-03-09 中国科学院生态环境研究中心 Laser induced fluorescence and light absorption bifunction detecting microflow controlled electrophoresis ehip
KR100819452B1 (en) * 2006-12-07 2008-04-04 이화여자대학교 산학협력단 Microfluidic device containing fluorescent chemosensor and method of optical detection for heavy metal ions by using the same
CN102331419A (en) * 2011-03-25 2012-01-25 上海汶昌芯片科技有限公司 Heavy metal ion detection chip and preparation method
CN103674902A (en) * 2013-12-12 2014-03-26 中国科学院半导体研究所 LSPR (Localized Surface Plasmon Resonance) portable biochemical detector based on mobile phone platform
CN103901006A (en) * 2014-03-26 2014-07-02 华南师范大学 ZnO quantum dot-based reagent and method for detecting cadmium ions
CN104096602A (en) * 2014-06-03 2014-10-15 青岛博睿林新材料有限公司 Microfluidic chip able to detect cadmium ions
CN104237210A (en) * 2013-06-08 2014-12-24 北京百康芯生物科技有限公司 Portable detection device
CN104777159A (en) * 2015-03-13 2015-07-15 浙江大学 Paralytic shellfish toxin detection method based on image analysis
CN104931440A (en) * 2015-06-12 2015-09-23 中国科学院合肥物质科学研究院 Portable high-sensitivity heavy metal detecting device based on micro-fluidic chip
CN110186880A (en) * 2019-04-18 2019-08-30 浙江大学 The cadmium ion detection kit and its application of CdTe/CdS core-shell quanta dots based on EDTA etching

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1591001A (en) * 2003-08-29 2005-03-09 中国科学院生态环境研究中心 Laser induced fluorescence and light absorption bifunction detecting microflow controlled electrophoresis ehip
KR100819452B1 (en) * 2006-12-07 2008-04-04 이화여자대학교 산학협력단 Microfluidic device containing fluorescent chemosensor and method of optical detection for heavy metal ions by using the same
CN102331419A (en) * 2011-03-25 2012-01-25 上海汶昌芯片科技有限公司 Heavy metal ion detection chip and preparation method
CN104237210A (en) * 2013-06-08 2014-12-24 北京百康芯生物科技有限公司 Portable detection device
CN103674902A (en) * 2013-12-12 2014-03-26 中国科学院半导体研究所 LSPR (Localized Surface Plasmon Resonance) portable biochemical detector based on mobile phone platform
CN103901006A (en) * 2014-03-26 2014-07-02 华南师范大学 ZnO quantum dot-based reagent and method for detecting cadmium ions
CN104096602A (en) * 2014-06-03 2014-10-15 青岛博睿林新材料有限公司 Microfluidic chip able to detect cadmium ions
CN104777159A (en) * 2015-03-13 2015-07-15 浙江大学 Paralytic shellfish toxin detection method based on image analysis
CN104931440A (en) * 2015-06-12 2015-09-23 中国科学院合肥物质科学研究院 Portable high-sensitivity heavy metal detecting device based on micro-fluidic chip
CN110186880A (en) * 2019-04-18 2019-08-30 浙江大学 The cadmium ion detection kit and its application of CdTe/CdS core-shell quanta dots based on EDTA etching

Non-Patent Citations (7)

* Cited by examiner, † Cited by third party
Title
FANG LI 等: ""Three-dimensional microfluidic paper-based device for multiplexed colorimetric detection of six metal ions combined with use of a smartphone"", 《ANALYTICAL AND BIOANALYTICAL CHEMISTRY》 *
HAITAO ZHANG 等: ""Selective fluorimetric detection of cadmium in a microfluidic device"", 《MICROCHEMICAL JOURNAL》 *
SI-NAN WANG 等: ""Fluorescence turn-on sensing of trace cadmium ions based on EDTA-etched CdTe@CdS quantum dot"", 《SPECTROCHIMICA ACTA PART A: MOLECULAR AND BIOMOLECULAR SPECTROSCOPY》 *
WON-IL LEE 等: ""A smartphone fluorescence imaging-based mobile biosensing system integrated with a passive fluidic control cartridge for minimal user intervention and high accuracy"", 《LAB ON A CHIP》 *
王冠 等: ""基于印迹聚合物的微流控量子点纸基芯片检测环境中的镉、铅离子"", 《分析试验室》 *
王心怡 等: ""基于EDTA 蚀刻的CdTe/CdS量子点荧光探针检测水环境中痕量镉离子"", 《传感技术学报》 *
苟彤: ""基于智能手机的手持式PCR系统开发及其应用研究"", 《中国优秀硕士学位论文全文数据库 基础科学辑》 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115161019A (en) * 2022-05-11 2022-10-11 华中农业大学 Preparation method of nitrogen-doped luminescent carbon quantum dot and application of nitrogen-doped luminescent carbon quantum dot in rapid detection of lysine content in pig serum

Also Published As

Publication number Publication date
CN110940645B (en) 2021-10-19

Similar Documents

Publication Publication Date Title
WO2014099629A1 (en) Rapid blood testing platform for use with mobile electronic devices
CN110824165B (en) Lung cancer tumor marker detection device and method based on micro-fluidic chip and mobile phone
TW201821616A (en) Method and device for inspecting microorganism
CN110940645B (en) Portable fluorescence sensing platform for cadmium ion detection and detection method
CN204128953U (en) Auto injection gas phase molecular absorption spectrometer
CN106404733A (en) Mobile intelligent terminal-based food safety detection device and method
CN104655546B (en) A kind of milk somatic cell method of counting and system based on mobile device
CN115876738A (en) Aptamer fluorescent brain natriuretic peptide detection device and sensing method based on smart phone
CN203949870U (en) A kind of liquid physical and chemical parameter measurement mechanism based on fluorescence analysis
CN104655620B (en) Gas-detecting device and detection method based on smart mobile phone and dyeing sensor array
CN111635931A (en) Multi-target miRNA detection micro-fluidic chip, detection method and rapid quantitative detection system thereof
CN107664631A (en) The preparation of equipment, detection method and its sample based on smart mobile phone detection biological marker
CN107389644A (en) A kind of rapid fluorescence proportioning device
CN106198468B (en) Electrochemistry-fluorescence is combined detection method in the case of a kind of list drop
CN209280566U (en) A kind of dry air formaldehyde in-situs tester
CN109406460B (en) Device and method for detecting content of chlorophyll a in water body
CN104330358A (en) Micro-flow cell for detecting ECL (electrochemiluminescence) signal of printing electrode and application of micro-flow cell
CN101995481A (en) Fast detector for ultra-trace disease markers
CN211697503U (en) Portable water heavy metal ion detection device matched with intelligent equipment for use
CN112924421A (en) Resonance light scattering detection analysis method and detection device of nucleic acid aptamer sensor
US20150125899A1 (en) Fluorescence-assisted counting apparatus for qualitative and/or quantitative measurement of fluorescently tagged particles
CN206431051U (en) A kind of fluorescence detector
CN107064116B (en) A kind of electrochemical luminescence biochemical detection system and method based on mobile phone USB-OTG interface
CN221038711U (en) Detection device, detection system comprising same and biological reaction system
CN218726684U (en) Sludge detection device

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant